Light guide apparatus of backlight module

ABSTRACT

A light guide apparatus of a backlight module is provided. The light guide apparatus includes a light guide plate and a plurality of LEDs serving as light sources disposed at one lateral side of the light guide plate. The light guide plate includes a circuit configured thereon, and the light sources are welded on the circuit of the light guide plate.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of and claims thepriority benefit of a prior application Ser. No. 12/464,104, filed onMay 12, 2009, now allowed. The entirety of the above-mentioned patentapplication is hereby incorporated by reference herein and made a partof this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light guide structure including alight guide plate and a light source, and being adapted for a backlightmodule.

2. The Prior Arts

Backlight modules are now widely used in many kinds of electronicproducts. For example, displays of notebook computers, mobile phones,and liquid crystal televisions do not emit light by themselves, andrequire backlight modules for providing light sources.

A typical backlight module includes a light guide plate and a lightsource. Light emitting diodes (LED) are often employed serving as lightsources of backlight modules for those electronic products demanding arelatively thin thickness. With respect to such a backlight module, theLED light source is positioned at a lateral side of the light guideplate. The light guide plate has a first surface and a second surfaceopposite to the first surface. A reflective sheet is provided at thefirst surface, and a plurality of optical sheets including a diffusingsheet and a prism sheet are provided at the second surface. An outerframe is provided for framing all of the components. In operation, theLED light source emits a light, and the light is inputted into lightguide plate from the lateral side of the light guide plate. A part ofthe light is reflected by the reflective sheet, and sequentially passesthrough the diffusing sheet and the prism sheet, and is then outputtedtherefrom.

When serving for a backlight module having a relatively small area, thelight sources are usually provided at one lateral side of the lightguide plate. However, when serving for a backlight module having arelatively large area, if the light sources are only provided at oneside of the light guide plate, the light inputted into the light guideplate gradually attenuates while being transmitted to the other side ofthe light guide plate. This often causes a nonuniform illuminatingcondition of the light guide plate. As such, a large size light guideplate is often provided with light sources at both sides for solving theproblem of the single side light sources.

FIG. 1 is a schematic diagram illustrating a conventional backlightmodule including a light guide plate and light sources assembledtogether. Referring to FIG. 1, no matter the light sources are providedto one side, two sides, or even more sides of the light guide plate 1,the conventional backlight module is generally configured by providingLEDs 2 onto a circuit board 3, and then assembling the LEDs 2 and thecircuit board together to the lateral side(s) of the light guide plate1. Accordingly, in fabricating such a backlight module, the LEDs 2 mustbe previously welded to the circuit board 3. Then, the circuit board 3,together with the LEDs 2 welded thereon, is secured to the light guideplate 3. As such, the process of the fabrication is relatively complex,and needs a high fabrication cost.

SUMMARY OF THE INVENTION

A primary objective of the present invention is to provide a solution tothe problem of the conventional backlight module, in which thefabrication process of providing the LEDs serving as light sources tothe light guide plate is complex and costly.

According to the present invention, the backlight module includes aplurality of LEDs, a circuit, and a light guide plate. The circuit isadapted for controlling the light source of the backlight module and isdirectly configured on the light guide plate, and then the LEDs aredirectly welded to circuit contacts of the circuit that are distributedat one side of the light guide plate. In such a way, the process of theassembling the LEDs and the light guide plate is simplified.

According to an embodiment of the present invention, a circuit forcontrolling on/off state or light emitting sequence of the backlightmodule is configured on light guide plate. Then, the light guide plateis further provided with contacts at one side, two sides, or more sidesof the light guide plate for connecting with the circuit. Then, LEDshaving electrical contacts are fixed to the light guide plate bydirectly welding the electrical contacts of the LEDs to the contacts ofthe light guide plate, respectively.

According to another embodiment of the present invention, the lightguide plate is configured with at least one recess at a lateral side forproviding a light source. The contacts of the circuit are arranged atboth sides of the recess or even inside the recess, and the LED is alsoreceived inside the recess. The electrical contacts of the LED are thenwelded to the contacts of the circuit. In such a way, the backlightmodule can achieve a further minimized size.

According to still another embodiment of the present invention, thelight guide plate is configured with at least one hole inside the lightguide plate at a lateral side for providing a light source. The contactsof the circuit are arranged at both sides of the hole or even inside thehole, and the LED is also received inside the hole. The electricalcontacts of the LED are then welded to the contacts of the circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art byreading the following detailed description of a preferred embodimentthereof, with reference to the attached drawings.

FIG. 1 is a schematic diagram illustrating a conventional backlightmodule including a light guide plate and light sources assembledtogether.

FIG. 2 is a schematic view showing that the LEDs are directly welded toone lateral side of a light guide plate according to an embodiment ofthe present invention.

FIG. 3 is a schematic view showing that the LEDs are directly welded totwo lateral sides of the light guide plate according to an embodiment ofthe present invention.

FIG. 4 is a schematic view showing the light guide plate including aplurality of holes at one side of the light guide plate and LEDsdirectly welded in the holes, according to an embodiment of the presentinvention.

FIG. 5 is a schematic view showing the light guide plate including aplurality of holes at a center area of the light guide plate and LEDsdirectly welded in the holes, according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 2 is a schematic view showing that the LEDs are directly welded toone lateral side of a light guide plate according to an embodiment ofthe present invention. Referring to FIG. 2, the present inventionprovides a light guide apparatus of a backlight module. According to anembodiment of the present invention, the light guide apparatus includesa light guide plate 1, and a plurality of LEDs 2 provided at least onelateral side of the light guide plate 1. The light guide plate 1includes a plurality of recesses 11 configured at one lateral side ofthe light guide plate. Each of the recesses 11 includes two circuitcontacts 12 distributed at two sides of the recess 11. The light guideplate 1 further includes a circuit for controlling an on/off state and alight emitting sequence of the LEDs 2 distributed thereon. Specifically,the LEDs 2 are respectively disposed on supporters 21. Each of thesupporters 21 includes two electrical contacts at both sides of thesupporter 21. The electrical contacts of the supporters 21 are thendirectly welded to the circuit contacts 12. According to an aspect ofthe embodiment, when the light guide plate 1 has a relatively largearea, for obtaining sufficient incident light, the light guide apparatuscan be modified as shown in FIG. 3. FIG. 3 is a schematic view showingthat the LEDs are directly welded to two lateral sides of the lightguide plate according to an embodiment of the present invention. Asshown in FIG. 3, the LEDs 2 are provided at two opposite lateral sidesof the light guide plate 1. In other embodiments, the LEDs 2 can beprovided at every lateral side of the light guide plate 1 for inputtingmore light into the light guide plate 1.

FIG. 4 is a schematic view showing the light guide plate including aplurality of holes at one side of the light guide plate and LEDsdirectly welded in the holes, according to an embodiment of the presentinvention. Referring to FIG. 4, a plurality of holes 13 are configuredinside the light guide plate 1 and adjacent to a lateral side of thelight guide plate 1. Each of the holes 13 is provided with circuitcontacts 12 at both sides of the hole 13 on the light guide plate 1. Theelectrical contacts of each of the supporters 21 are then welded to thecircuit contact 12, so as to secure the LEDs 2 inside the holes 13. Theholes 13 can be distributed inside the light guide plate 1 adjacent toone lateral side of the light guide plate 1, and can also bealternatively distributed separately adjacent to two opposite lateralsides or more lateral sides of the light guide plate 1.

FIG. 5 is a schematic view showing the light guide plate including aplurality of holes at a center area of the light guide plate and LEDsdirectly welded in the holes, according to an embodiment of the presentinvention. Referring to FIG. 5, the holes 13 are configured at thecenter area of the light guide plate 1. Each of the holes 13 is providedwith circuit contacts 12 at both sides of the hole 13 on the light guideplate 1. The electrical contacts of each of the supporters 21 are thenwelded to the circuit contact 12, so as to secure the LEDs 2 inside theholes 13. Preferably, two neighboring LEDs 2 are positioned in oppositedirections for emitting lights toward opposite directions in the lightguide plate 1, respectively. In such a way, the light guide plate 1 canbe uniformly illuminated by the LEDs 2.

Although the present invention has been described with reference to thepreferred embodiments thereof, it is apparent to those skilled in theart that a variety of modifications and changes may be made withoutdeparting from the scope of the present invention which is intended tobe defined by the appended claims.

1. A light guide apparatus for a backlight module, comprising: a lightguide plate configured with a recessed compartment and a circuit contactnear the recessed compartment; and a light source disposed at therecessed compartment and electrically connected to the circuit contact.2. The light guide apparatus as claimed in claim 1, wherein the recessedcompartment is a recess.
 3. The light guide apparatus as claimed inclaim 1, wherein the recessed compartment is a hole.
 4. The light guideapparatus as claimed in claim 1, wherein the recessed compartment isdisposed at a lateral side of the light guide plate.
 5. The light guideapparatus as claimed in claim 1, wherein the recessed compartment isdisposed adjacent to a lateral side of the light guide plate.
 6. Thelight guide apparatus as claimed in claim 1, wherein the recessedcompartment is disposed near the center area of the light guide plate.7. The light guide apparatus as claimed in claim 6, wherein the lightsource emits lights toward the lateral side of the light guide plate. 8.The light guide apparatus as claimed in claim 1, further comprising asupporter on which the light source is disposed.
 9. The light guideapparatus as claimed in claim 8, wherein the supporter is configuredwith an electrical contact connected to the circuit contact by welding.10. The light guide apparatus as claimed in claim 1, further comprisinga circuit configured on the light guide plate whereas the circuitcontact is a part of the circuit.
 11. A light guide apparatus for abacklight module, comprising: a light guide plate configured with aplurality of recessed compartments and a plurality of circuit contactsnear the recessed compartments, respectively; and a plurality of lightsources disposed at the plurality of recessed compartments andelectrically connected to the plurality of circuit contacts,respectively.
 12. The light guide apparatus as claimed in claim 11,wherein the plurality of recessed compartments are recesses.
 13. Thelight guide apparatus as claimed in claim 11, wherein the plurality ofrecessed compartments are holes.
 14. The light guide apparatus asclaimed in claim 11, wherein the plurality of recessed compartments aredisposed at the lateral side of the light guide plate.
 15. The lightguide apparatus as claimed in claim 11, wherein the plurality ofrecessed compartments are disposed adjacent to the lateral side of thelight guide plate.
 16. The light guide apparatus as claimed in claim 11,wherein the plurality of recessed compartments are disposed near thecenter area of the light guide plate.
 17. The light guide apparatus asclaimed in claim 16, wherein the plurality of light sources emit lightstoward the lateral side of the light guide plate.
 18. The light guideapparatus as claimed in claim 11, further comprising a plurality ofsupporters on which the plurality of light sources are disposed,respectively.
 19. The light guide apparatus as claimed in claim 18,wherein each of the plurality of supporters is configured withelectrical contacts connected to the corresponding ones of the pluralityof circuit contacts by welding, respectively.
 20. The light guideapparatus as claimed in claim 11, further comprising a circuitconfigured on the light guide plate whereas the plurality of circuitcontacts is a part of the circuit.